Study of establishment and regeneration of forest by DNA polymorphism analysis and isotopic tracer

本研究为了解树木和外生菌根真菌的繁殖机制积累了知识。这些知识的积累将为从遗传多样性保护和利用外生菌根真菌共生功能的角度出发的天然林更新新方法奠定基础。本研究的主要成果如下：1.树木的繁殖机制：微卫星多态性分析揭示了几种先锋植物的繁殖机制，如在富士山火山沙漠中的虎杖和柳，以及在干燥河床中的先锋树刺槐。本文还研究了热带先锋树种白千层有性生殖与无性生殖的平衡。结果表明，该平衡受环境条件的影响。研究了冲绳一种红树林红海榄的遗传分化.复制我 ...更多信息 外生菌根真菌的动态：在落叶松人工林中，研究了灰盖乳牛肝菌（Suillusgrevillei）的繁殖机制，发现其根外菌丝在单个子实体下呈斑块状分布，并在一年内降解。此外，地下菌根群落由斑块状的菌根菌丝体组成，形成马赛克。在富士山火山荒漠中，发现了大量的外生菌根孢子果和根尖，原生植被的演替伴随着外生菌根真菌群落的演替。外生菌根真菌的种类组成与子实体真菌的种类组成基本一致。微卫星分析表明，牛硬皮肿腿蜂首先通过偶然的长距离孢子传播在植被斑块的边缘建立起其种群，然后通过根外菌丝的延伸扩大其种群。在荒漠不同地点进行的寄主树幼苗种植试验表明，已建立的外生菌根寄主树有利于新幼苗的生长和成活.外生菌根共生体系中的示踪实验：我们利用成像板放射自显影技术对外生菌根共生体系中的光合产物进行了示踪<14>，并获得了光合产物向根外菌丝体转运的一些有趣的发现. DNA多态性分析方法的改进：首次将末端限制性片段长度多态性（Terminal-RFLP）技术成功地应用于真菌种的鉴定。此外，一种新的技术，使每个人都能够开发micorsatellite标记更容易被建立。这项技术可以应用于广泛的物种。少

The present research accumulated knowledge about the reproduction mechanisms of trees and ectomycorrhizal fungi. Such knowledge accumulation would lay the basis for new methods of natural forest regeneration that stand at the viewpoints of genetic diversity preservation and application of symbiotic function of ectomycorrhizal fungi. Outcomes of the present research are summarized as follows :1. Reproduction mechanisms of trees : Microsatellite polymorphism analyses revealed reproduction mechanisms of several pioneer plants, such as Polygonum cuspidatum and Salix reinii, in volcanic desert on Mount Fuji, and a pioneer tree, Robinia Pseudoacacia in a dry riverbed. The balance between sexual and asexual reproductive manners in a tropical pioneer tree Melaleuca cajuputi was also investigated. The results indicated that the balance was influenced by environmental conditions. The genetic differentiation of a mangrove tree Rhizophora stylosa in Okinawa was also investigated.2. Reproduction me … More chanisms of ectomycorrhizal fungi : In a Larlx stand, we investigated the reproduction mechanism of Suillus grevillei, and found that its extraradical mycelia are present patchily under individual sporocarps and degraded within one year. Also, underground mycorrhizal communities were composed of patches of mycorrhizal mycelia, forming a mosaic. In the volcanic desert on Mount Fuji, we found a lot of ectomycorrhizal sporocarps and root tips, and that primary vegetation succession was accompanied with succession of the ectomycorrhizal fungal community. In this site, fungal species composition among ectomycorrhizae is rather consistent with that among sporocarps. Microsatellite analysis of Scleroderm bovista showed that this fungus first establishes its genet s at the periphery of vegetation patches by accidental long-distance spore dispersal and thereafter expands its occupation by extension of extraradical mycelia. Planting experiments of host tree seedlings on various places of the desert demonstrated that established ectomycorrhizal host trees facilitate the growth and survival of new seedlings.3. Tracer experiments in ectomycorrhizal symbiotic system : We traced the photosynthates in an ectomycorrhizal symbiotic system after feeding ^<14>CO_2 by autoradiography with imaging plates, and obtained some interesting findings on photosynthate translocation to extraradical mycelia.4. Improvements of DNA polymorphic analyses : We first introduced successfully Terminal-RFLP into identification of fungal species. Also, a new technique that enabled everyone to develop micorsatellite markers much easily was established. This technique can be applied to a wide range of species. Less